diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/service/VtnRscService.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/service/VtnRscService.java
new file mode 100644
index 0000000..21161ba
--- /dev/null
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/service/VtnRscService.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.vtnrsc.service;
+
+import java.util.Iterator;
+
+import org.onlab.packet.MacAddress;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.HostId;
+import org.onosproject.vtnrsc.SegmentationId;
+import org.onosproject.vtnrsc.TenantId;
+import org.onosproject.vtnrsc.VirtualPortId;
+import org.onosproject.vtnrsc.event.VtnRscListener;
+
+/**
+ * Service for interacting with the inventory of Vtn resource.
+ */
+public interface VtnRscService {
+    /**
+     * Adds the specified listener.
+     *
+     * @param listener VtnRsc listener
+     */
+    void addListener(VtnRscListener listener);
+
+    /**
+     * Removes the specified listener.
+     *
+     * @param listener VtnRsc listener
+     */
+    void removeListener(VtnRscListener listener);
+
+    /**
+     * Returns the SegmentationId of tenant.
+     *
+     * @param tenantId tenant identifier
+     * @return SegmentationId the SegmentationId of tenant
+     */
+    SegmentationId getL3vni(TenantId tenantId);
+
+    /**
+     * Returns Classifier Ovs list of the specific tenant.
+     *
+     * @param tenantId tenant identifier
+     * @return iterable collection of Device
+     */
+    Iterator<Device> getClassifierOfTenant(TenantId tenantId);
+
+    /**
+     * Returns Service function forwarders Ovs list of the specific tenant.
+     *
+     * @param tenantId tenant identifier
+     * @return iterable collection of Device
+     */
+    Iterator<Device> getSFFOfTenant(TenantId tenantId);
+
+    /**
+     * Returns gateway mac address of the specific host.
+     *
+     * @param hostId host identifier
+     * @return MacAddress of host
+     */
+    MacAddress getGatewayMac(HostId hostId);
+
+    /**
+     * Checks if a specific port is a service function.
+     *
+     * @param portId port identifier
+     * @return true or false
+     */
+    boolean isServiceFunction(VirtualPortId portId);
+
+    /**
+     * Returns device identifier mapping to the specific port.
+     *
+     * @param portId port identifier
+     * @return device identifier
+     */
+    DeviceId getSFToSFFMaping(VirtualPortId portId);
+}